Intrinsic Device Protection - Siemens SIRIUS 3RW50 Manual

7.5

Intrinsic device protection

Operating principle
The integrated intrinsic device protection protects the power semiconductors as well as the
bypass contacts against impermissible overload. If the internal warning limit is exceeded, a
message is output on the 3RW50 soft starter. If the internal fault threshold is exceeded, the
3RW50 soft starter will switch off automatically.
NOTICE
Property damage due to short circuits.
The intrinsic device protection system does not protect against irreparable equipment
damage caused by short circuits.
Connect semiconductor fuses upstream in order to protect the power semiconductors
against irreparable damage by short circuits (e.g. in case of cable damage or an interturn
fault in the motor).
Recovery time after device protection is triggered
If the 3RW50 soft starter shuts down because the motor overload protection or the intrinsic
device protection trips, you must wait a defined cooling time (recovery time) prior to
acknowledging the fault or restarting the motor.
● In the event of power semiconductor overload: 30 s
● In the case of bypass overload: 60 s
SIRIUS 3RW50 soft starter
Manual, 09/2019, A5E35628455002A/RS-AA/001
Functions
7.5 Intrinsic device protection
129